Advanced Bionics is the only U.S. manufacturer of cochlear implants, which restore functional hearing to patients with profound sensorineural deafness. The CLARION implant employs the most sophisticated multichannel speech processing system available, but clinical performance of this and competing devices tends to be limited by relatively poor selectivity of the multichannel electrode. The external speech processor filters the acoustic signal into parallel channels of electrical stimulation that are intended to activate separate populations of auditory neurons when transmitted to the multichannel electrode implanted in the inner ear. A novel electrode has been designed that should substantially improve channel selectivity; a novel method for fabricating such electrodes has been developed. Animal-scale electrodes will be designed, built and implanted chronically in cats; post-mortem histological analysis will evaluate the safety of this novel strategy. Human-scale electrodes will be designed, built and tested for surgical handling properties. If feasibility is demonstrated, selective electrodes will then be evaluated in deaf patients as part of functional cochlear implant systems. The goal of this research is a substantial improvement in the quality of sound provided by cochlear implants, permitting an even higher percentage of recipients to function normally in hearing society.